President Obama’s brief statement Monday evening on the deadly bombings that struck near the finish line of the Boston Marathon earlier in the day gave few clues concerning the investigation into the attacks.

But three themes the president homed in on are likely to echo through the days ahead. Boston is a resilient city and will overcome this tragedy, no one should rush to conclusions about who is behind the attack, and whoever did it will be found out and will be “held accountable.”

Terrorism experts said the attack, which killed three people and left more than 100 injured, some critically, had some of the hallmarks of a “lone wolf” or perhaps an ad hoc domestic group – but that it was also way too early to rule out individuals or a group affiliated or inspired by Al Qaeda or one of its regional organizations.

“This [attack] has some of the ring of Al Qaeda, but it also has the earmarks of a lone wolf,” says Juan Zarate, a former deputy national security adviser for combating terrorism under President George W. Bush.

The symbolism and high visibility of the Boston Marathon finish line are reminiscent of Al Qaeda targeting, he says, but other factors – that the attack was carried out on April 15, the federal income tax deadline and what in Massachusetts is Patriots Day – could also suggest the work of a disgruntled lone wolf or domestic anti-government groups.

National security analyst Peter Bergen said on CNN that the attack could be the work of “right-wing extremists.” For the so-called “patriot” groups, anything from tax day to the heated national debate on gun regulations could have been the triggers for such an attack.

Some analysts even noted that the attacks were carried out at about the 26-mile marker of the race – which had been dedicated to the 26 victims in Newtown, Conn., which has moved to the center of the gun-regulation debate.

But for Mr. Zarate, now a transnational threats and homeland security expert at the Center for Strategic and International Studies in Washington, other recent terror attacks or thwarted attacks also serve as reminders that this could have been perpetrated by several groups – or individuals.